PURPOSE: To provide a refuse bag capable of being easily and quickly closed by forming the separable cutting line of a sine waveform on a tube.

CONSTITUTION: On a folded tube 10, a joining end 24 orthogonal to the extension direction of the tube 10 and an intermediate or separable cutting line 34 provided with the shape of 1/4 of the sine waveform are formed. The joining end 24 joins the tube 10 lying one over the other and is accompanied by a cutting line as well. When the tube 10 is cut along the joining end 24 and the intermediate or separable cutting line 34, these two refuse bags 38 and 40 are formed. Then, when the respective refuse bags are opened, four tie parts and four cuts are formed at the opening part. When the refuse bag is filled with refuse, the four tie parts are tied together and the refuse bag is closed.